Many containers used with produce or meat are wax coated or wax impregnated. This allows the meat or produce to be iced during storage and transportation. The containers are wax coated or wax impregnated either by passing the individual container blanks through a molten wax bath or by carrying the individual container blanks through a hood in which the molten wax is sprayed or cascaded onto the blank. These wax applications are slow because the containers must be completely saturated with the molten wax and the molten wax cooled before the container leaves the process. The containers can then be stacked and bundled without adhering to each other. Because the process is slow and time constrained and because the apparatus has a fixed dimension, the number of container blanks which may be wax saturated during any given time period is limited by the size of the apparatus.
The containers often are required on a seasonal basis and it usually is desirable to have high and low production periods depending on when the containers are needed. This is not possible normally because only a fixed number of blanks can be treated in a given time period. It is then necessary either to have continuous production throughout the year and carry inventory, to run additional shifts in order to obtain the desired number of wax saturated containers when they are needed or to have an oversized apparatus.
These containers often are used in locations such as a produce field where it is difficult to tape or glue the bottom closure panels. For this reason regular slotted containers (RSC) which normally are stitched or glued are not used. A regular slotted container with a snap lock bottom closure is used instead.
Buerger, U.S. Pat. No. 2,513,079 granted June 27, 1950; Sax, et al, U.S. Pat. No. 3,960,313 granted June 1, 1976 and Stolkin, et al, U.S. Pat. No. 4,007,869 granted Feb. 15, 1977 show snap lock bottom closures. The Buerger patent is exemplary. In this patent the fold-back flaps 42 and 43 are adhered to their adjacent flaps and when the container is squared the bottom closure snaps into place. The snap lock bottom requires additional fold-back and adhering operations in its manufacture.
The snap lock bottom type constructions require spot gluing with specific placement of the adhesive if the container is to function properly. The snap lock bottom also requires nonrectangular adhesive patterns. In a wax saturated container the adhesive must be of a special type in order to fasten to the fibers in the containerboard.
The Buerger patent also discloses the nesting of the top closure panels on the web. Other patents which describe nesting of blanks on a web are FIGS. 8-10 of Schillinger, U.S. Pat. No. 3,679,124 granted July 25, 1972; Demby, et al, U.S. Pat. No. 3,285,492 granted Nov. 15, 1966; and British Pat. No. 859,905 published Jan. 25, 1961.